Dental vulcanizer and celluloid-press.



No. 659,747 Patented Oct. IB, |900.

H. HARTWIG A. W. FELTMANN.

DENTAL VULCANlZER AND GELLULOID PRESS.

(Application led Nov. 4, 1899.)

gw@ i NTTE STATES PATENT OFFICE.

HENRY HARTWIG AND ADAM WM. FELTMANN, OF CHICAGO, ILLINOIS.

DENTAL VULCANIZER AND CELLULOlD-PRESS.

SPECIFICATION forming part of Letters Patent No. 659,747, dated October16, 1900.

Application filed November 4, 1899. Serial No. 735,852. (No model.)

To all wtont t may concern:

Be it known that we, HENRY HARTWIG and ADAM WM. FELTMANN, citizens ofthe United States, residing at Chicago, Cook county, Illinois, haveinvented certain new and useful Improvements in Dental Vulcanizers andCelluloid-Presses, which are fully set forth in the followingspecification, reference being had to the accompanying drawings, forminga part thereof.

The purpose of this invention is to provide an improved apparatus in thenature of a dental vulcanizer aud celluloid-press for forming andvulcanizing Celluloid and rubber plates for dental work.

In the drawings, Figure lis a vertical axial section of our improvedpress and vulcanizer. Fig. 2 is a detail side elevation, partlysectional, in a plane at right angles to that of the section in Fig. l.Figs. 3 and 4. are detail sections at the line 3 4in Fig. l, showing thenut-closing cam-plate in plan view in its two positions.

A is the pot or crucible.

B is the cupola or dame-dome, into which the pot A is inserted and bywhich it is supported and exposed to the ame, which it is the purpose ofthe cupola to gather and direct about to the pot for the purpose 0iheating the same.

C is the cap or cover of the pot. It is provided with the customarymeans for making it tight at its junction with the upper edge of thepot, consisting of asbestos packing lodged in a groove C in the coverand forming the seat of the upper edge of the pot on the under side ofthe cover.

D is the clamp by which the cover C is bound to the pot. It is securedbya bolt D', hinged to the pot and adapted to swing up into engagementwith the notched end of the clamp, the other end of the clamp beingsecured bya bolt D2, inserted through the clamp and provided with anoperating-handle D20 The cap or cover C has a turret or hub C2 extendingup at the center to afford guidance and bearing for the screw-shaftH,which operates the disk or follower F, as hereinafter explained, inclosing up the flask or mold.

G is a plate which carries the flask within the pot. It is suspendedfrom the cap C by three rods G GQ screwed into the cap, and G2, pivotedto the cap, the rods G being inserted through the apertures g g iu theplate G and the rod G2 being arranged to be swung into the notch g' inthe plate G after the iiask or mold has been putin position on the plateG. The length of the rods G G2 is such as to support the plate G at ashort dist-ance above the bottom of the pot, so that the fiask or moldsupported on the plate is kept out of contact with the pot, being atsome distance both from its side walls and bottom. The cap C is recessedin the underside to accommodate the follower F when the latter iswithdrawn upwardto the highest point, as seen in Fig, l. The followerhas for its stem a screw-shaft H, to which it is connected so as to bedepressed and lifted by the latter, but not to be rotated by it, agroove h being made around the shaft near the lower end and keys I Ibeing inserted through the hub vF ofthe follower F, so as to extendtangentially past the opposite sides of the shaft, lodging in thegroove, being engaged half their diameter in the groove and half theirdiameter in the hub.

An important feature of this invention consists of the adaptation of thedevice to afford opportunity for the operator to test or sense thecondition of the substance in the moldthat is, as to whether it issoftened sufficiently to permit the mold to be forcibly closed upwithout danger of rupturng the same or displacing the teeth or otherinsets which may be lodged in it for the purpose of becoming embedded inlthe plate to be made thereinand also its adaptation to affordopportunity for the removal of the entireflask from the pot in orderthat the condition may be observed by the eye, as well as tested by thehand, without relieving the pressure upon the mold. These two resultsare accomplished by the structure shown, in which the mold is heldbetween the bottom plate G and Ithe follower F independently of anysupport on the por, either top or bottom, and by the provision, about tobe described, which permits the follower to be depressed directly by thehand of the operator 0n pressing the upper end of the screw-shaft andalso to be depressed forcibly by the rotation of the screwshaft and tobe locked by the nut or released therefrom at will. The upper portion ofthe IOO screw-shaft has a ratchet-thread H2, having its abrupt faceupward, so that when engaged with a corresponding nut it tends to resistupward pressure and is adapted, therefore, lobe operated to press downward withV a minimum liability to injure or jam the thread. The nut withwhich this ratchet-thread of the shaft is engaged is made of two parts JJ, for which a seat is provided by an aperture C21, extending throughthe hub C2 of the cover toward the upper end, so that the two parts ofthe nut may be moved apart or may be closed up upon the thread of theshaft. This two-part nut is retained in its seat by the nut K, which isscrewed into the upper end of the hub or turret C2 and has a fiange Kextending out over the upper end of the turret and serving to retain ina rabbet formed at the upper end of the latter a cam-plate L, which isprovided with a handle L', by which it may be rotated on the hub. Saidcamplate has -two oblique or eccentric slots L2 L2, into which projectstuds J J', rooted in the two parts, respectively, of the divided nut JJ. lt will be understood that the rotation of the cam-plate in onedirection will force the two parts of the nut apart, and its rotation inthe opposite direction will move them together and close them up uponthe screwshaft. In order to lock them in the latter position, the slotsL2 L2 at their inner ends terminate in a portion extending concentricwith respect to the axis of the parts for a sufficient distance to aorda seat for the studs, so that the outward pressure of the latter has notendency to crowd the cam-plate around in a direction to permit outwardmovement of the two parts of the nut.

Suitable packing M for the stem is provided at the recess C20 in theturret C, and the packing-nut C4 is screwed into the stem above suchpacking, and in order to obtain access to this nut to compress thepacking without removing the two-part nut and other elements at theupper end of the hub a transverse aperture is made at C5 entirelythrough the hub above the packing-seat, and the nut O4is provided withsockets c4 to permit its engagement by lever-pins to rotate it.

The mode of use of this device may be nnderstood by one familiar withthe details of dental vulcanizers and Celluloid-presses now in commonuse. The pot A is designed to contain a suitable amount of water, fromwhich when the pot is closed and exposed to the heat of the flame in thecupola steampressure is generated to any desired degree, producing anydesired temperature-for eX- ample,about 225 Fahrenheit for celluloid and320 Fahrenheit for rubber, these temperatures being suitable for thepurposes, respectively, of softening thecelluloid to cause it to takethe shape of the mold and of softening and vulcanizing the rubber. Theflask or mold of plaster-of-paris is supported on the plate Gr, thelower half or drag being lodged The cavity is suitably charged withthereon.

the celluloid or rubber to be molded or vulcanized and the cope or upperhalf of the mold or flask is placed in position above the drag and underthe follower F. The rod G2 is then latched in place and ihe cap holdingthe cage comprising the plate G and the suspending rods and nowcontaining the flask is now put in place over the pot, the cage and itscontents being suspended within the latter. The clamp being tighted andthe proper heat applied the operator will be able to determine bypressing upon the upper end of the screw-shaft when the divided nut isopen and the shaft is free therefrom whenthe cellnloid or rubber issuitably softened to yield to proper pressure and lill the cavity of themold without danger of rupturing the latter or displacing the teethwhich have been set therein. If it is difcult to\judge in this way inany instance, the operator will depress the follower by means ofpressure upon the upper end of the shaft to sjnch an extent as ismanifestly safe, and then closing up the nut to lock the shaft in thatposition he may open up the pot and withdraw' the cover and flaskcarried thereby and examine its condition without relieving the pressureby which the flask has been closed and therefore without changing itscondition -in any respect during such examination, and he can thenrestore the flask to the pot and close it up and raise it again to thenecessary "temperature to iin- `"ish the process. Whenever it isdetermined either by inspection or bylthe resistance felt by the hand inattempting to force the' iiask together by pressure on the screw-shaftthat the material is in a proper condition, the nut J J will be closedupon the shaft and the latter rotated to completely close up the flask,forcing out through the crevice between the drag and cope any excess ofmaterial.

The temperature being maiiitained for a sulii` cient time to effect thewulcanizing (when rubber isthe substance operated upon) the pot will ybeopened, the cover and flask withdrawn, the pressure being stillmaintained by the screw, and the flask may be cooled by being plungedimmediately into water. The advantage of this will be understood bythose accustomed to using the devices now in common use, in which thecooling can only be effected by cooling the pot before the removal ofthe flask therefrom. (Such cooling reducing the pressure in the'fpot,which is relied upon to hold the twoyparts of the flask together, theplate is liable to be sprung and it is therefore necessary in the use ofthese devices to allow the cooling to occur gradually, occupying severalhours and delaying the finishing of the work, whereas with our devicethe cooling can be effected within a very short time for the reasonsabove explained.

In order to avoid the accidents which arc so liable to occur in the useof the ordinary devices, operators are frequently led to suspend theprocess before the best tempelature in obtained for fear of exceeding asafe tem- IOG perature and spoiling the work. With our apparatus,however, no uncertainty need ever existas to whether the substance issufficiently fluid to effect the desired result before the flask isclosed up tight, and the flask being held securely closed by the screwit is possible and safe to continue the process to a higher temperaturethan would Ordinarily be risked were it not for this certainty. Theresult is a much tougher plate than can be produced when the flask isthus securely closed by pressure independent of that generated in thechamber in which the ask is exposed to the heating element.

In the celluloid-presses in common use the flask rests upon a frog orupraised boss on the bottom of the pot and the heat is thereby conducteddirectly through metal to the flask and that side of the iiask is almostcertain to be hotter than the remainder or to be heated in advance ofthe remainder. If the heat is continued therefore until the besttemperaiure is obtained throughout the remainder of the flask and thesubstance being molded z therein the proper temperature is liable to beexceeded at the lower side, especially along the lines corresponding tothe line of contact of the ask with the frog. The unequal temperaturenot only causes inequality in texture, but frequently causes fat-aldefects by reason of overheating at the lower side, and it is thereforea very important advantage of our device than no contact occurs betweenthe flask and the pot during the entire process.

When our apparatus. is employed for the purpose of molding andvulcanizing rubber plates, another important advantage is obtained byits use by reason of the opportunity it affords for closing up the flaskby means of the screw operated from the exterior when the temperature isat the highest point, or at least at the point Where the rubber is inthe best condition for taking the form of the mold-that is,approximately fluid. This advantage is that thereby the sulfuretedhydrogen gas which is generated in the rubber in the process ofvulcanizing and at the temperature indicated and which, failing toescape, renders the plate porous in the thicker parts is forced out bythe pressure applied to the rubber when it is at that stage in theprocess, and thereby the plate is rendered of substantiallyuniformdensity throughout both thinner and thicker portions. The presence andsubsequent working out of the sulfureted hydrogen gas from the platewhile it is being worn in the mouth is the cause or is at least commonlyunderstood tobe the cause of what is known to be"rubber sore mouth, andthe use of our apparatus in making these plates tends largely,therefore, to prevent rubber sore mouth resulting from the wearing ofthe plates thus made.

It will be evident upon consideration of this apparatus and the specificpurpose which it is intended to serve that it is not absolutelyessential to these purposes, or to some of them at least, that. the cageor means of suspending the tiask in the pot should be attached to thecover; but in order to close up the flask by means of the screw or othermechanical expedient operated from the -exterior and to hold it closedpositively while it is removed from the pot bodily it is necessary thatthe mechanical device by which the follower is advanced upon the flaskto close up the latter while such liask rests npon the support providedfor it must obtain its bearing and the resistance necessary to adapt itto close up the flask on a part which is connected to the support of theflask. In the structure shown the coveris the bearing for the devicetowit, the screw which advances the followerand the rods G G2 constitutethe connection from that bearing to the support of the flask-to wit, theplate G. Any structure in which there is a support for the flask and abearing for the element which advances the follower and a connectionbetween such bearing, and in which the entire structure comprising suchsupport and bearing and their connections is supported by the pot and inwhich the means for operating the mechanical device which advances thefollower is accessible outside the pot when the latter is closed by thecover will involve the essence of this feature of our invention.

We claim- 1. An apparatus for the purpose indicated, comprising a potand a cover adapted to be secured thereon, having suspended on its lowerside into the pot a support for the flask; a follower for closing up theflask having its stem extending through the cover and in position to beoperated by hand and means disengageably connected with the stem forholding it against withdrawal or advance under direct longitudinalpressure in either direction; whereby the condition of the materialwhich is molded in the flask may be tested by direct hand-pressure onthe stem, and mechanical power may be applied to compress it.

2 An apparatus for the purpose indicated, comprising a pot, a cover, anda flask-supporting cage suspended therefrom within the pot, a flaskwithin the cage, a stem for operating the follower extending out throughthe cover and threaded, and a divided nut mounted on the cover andadapted to be closed up to engage the threaded portion of the stem andto be opened to release the same at will.

3. In an apparatus for the purpose stated in combination with the potand means therein for supporting the flask, a follower adapted to beadvanced upon the flask to close it up and having a stem which extendsout through the cover and is threaded, and a divided nut mounted on thecover and stopped against movement longitudinally with respect to thestem, and adapted to be closed up to engage the latter and to be openedto release it, as well.

4. An apparatus for the purpose indicated,

comprising the pot, means for supporting the IOO IIO

IIS

iask therein, the follower within the pot and a stem for the sameextending out therefrom; mechanical means for operating upon the stemfor advancing the follower, adapted to be engaged therewith and releasedtherefrom at will; whereby the follower may be advanced by the hand ofthe operator and then engaged with the mechanical devices and retained,or further advanced, at will.

5. In combination with the pot and the cover for the same, the followerhaving its stem extending out through the cover, the latter having aseat, C21, extending transversely to the axis of the stem, the dividednut lodged in said seat, and the cam-plate L journaled about the steinand longitudinally stopped in respect to the axis of itsjournal-bearing, and having eccentric slots, L', L', the two parts ofthe nut having abutments which engage such slots, whereby the rotationof the plate opens and closes the nut.

6. In combination with the pot, the cover having the extended hub vorturret, the follower having its stern extended through such hub andthreaded on an upper portion of its length, a divided` nut mounted inthe turret, adapted,when closed up, to engage the threaded portion ofthe'` stem, and suitable means for closing it up, the hub, having apackingcavity below the seat of the divided nut, and threaded belowsaidseat; a nut to engage with such threaded portion to compress thepacking, the hub "foeing transversely apertured above the packing-seatand giving access to the packing-nut for the purpose of operating it. l

In testimony whereof we have hereunto set our hands, in the presence oftwo witnesses, at Chicago, Illinois, this 25th day of October, 1899. i

HENRY HARTWIG. A. WM. FELTMANN.

Witnesses: l

CHAs. S. BURTON, ODNA H. BOWEN, Jr.

